Method of forming articles of impregnated fiber



METHOD OF FORMINGARTICLES 0F IMPREGNATED FIBER.

APPLICATION FILED JUNE 21. 1311.

} UNITED STATES PATENT oi-"rics.

DAVID c. COLLIER, or SAN DIEGO, CALIFORNIA, assienou 'ro WILLIAM'H. SHEFFIELD,

or new YORK, N. Y.

METHOD FORMING ARTICLES 01 IMPREGHATED FIBER.

Specification 01 Letters Patent. Pate ted Mar, 22, 1921.

Application filed June '21, 1017. Serial manager.

' useful Improvements in Methods of Forming Articles of Impregnated Fiber,'of which the following is a specification.

This invention relates to the production of sheets, plates, boards, or other formed or shaped articles comprising a fibrous base im other containers etc. An illustrative empregnated with an agent which preferably at least has cementitious properties, and is capable of acting as a binder for the fiber, or as a watxproofing agent therefor, or is capable of imparting fire-resisting qualities to a combustible fiber. My inventioncomprises a method of producing such impr'eg nated sheets, articles, or like bodies, and will be described by reference to certain illustrative embodiments thereof, it being understood that the invention is not restricted to the manipulative details hereinafter described, or to any particular proportions of the components, which will necessarily vary widely according to the intended use of the product. The invention is applicable to the production of a great variety of articles, in-

cluding building-boards, sheets or plates,

roofing materials, aeroplane win s, various hollow art1cles,including bottles, rums, and

bodiment of m invention is as follows A suitable brous material, for example wood pulp, sulfite fiber, other vegetable fiber, or fibrous asbestos, is beaten up pended in water and. then deposited upon a suitable foraminous support, for example a metallic cloth or screen, the meshes of which are sufiiciently small to retain the fiber; or

other fabric or porous body may be used, Suction is applied beneath this sup ort insuch manner and in such degree that t e fiber is deposited upon the support in. a highly compact and closely interlaced condition, theliquid draining through the support. In

this way any desired thickness of fibrous sheet or body may be built up. The foraminous support may have any desired form or contour according to the shape of the ar ticle to be produced, consisting for example of a flat or curved sheet, a hollow form or the, like. In the latter case the fiber may be deposited either upon the outside or upon and susthe insideof the form, the suction being of.

course applied to the opposite side of the supplort.

e impregnation of the fibrous body thus formed is carried out without removin it from the foraminous support, and eit er with or without preliminary drying, according to the nature of the impregnatin solution. If the latter is an aqueous so ution,

preliminary drying will not as a rule be necessary; whereas'drying is desirable or -necessary when non-aqueous varnishes or solutions are used for impregnation. In any casethe impre nation is preferably carried out while the ber layer is still held by the suction against its foraminous support,

since thereby an pulping or loss of compactness of the ber is prevented, while on the other hand, an extremely rapid,

thorough and intimate impregnation is secured. The impregnating liquid or solution is caused to flow through the body of the fibrous sheet or article until a complete andv uniform impregnation is secured.

phaltic, resinous or other varnishes, rubber solutions, etc., may be used.

A highly advantageous embodiment'of the invention is carried into effect as follows:

The fiber, either before being suspended in water or .after being so suspended and before I being deposited upon the foraminous support, is intimately mixed with a small proportion, say 1-15 per cent., more or 1ess, of calcined magnesia. Suction is then applied to the opposite side of the support, and the mixture of fiber and magnesia is deposited thereon in the form of a highly compact bed or layer. A magnesium chlorid solution, for example the bittern water which is the usual byproduct of seaside salt works is then drawn through this .bed, whereby the magnesia contained therein is converted into the highly cementitious oxychlorid, the bed being in the meantime strongly compacted,

under the suction. In .this operation, as in those before described, it is desirable to employ as higha degree of vacuum as is pracically attainable, since .the higher the vacuum the more compact the deposit will be. The suction may be maintained until the oxychlorid cement has set sufiiciently to prevent any material loosening of the bed or loss of compactness when the pressure upon the two sides is equallzed.

While I prefer in all cases to bring about v the deposition of the fibrous bed or layer as for egrample a wire mesh or the like. For

this purpose it is only necessary to put the reinforcing member in its proper position upon the foraminous bed, and then to apply the fib'er as before until the reinforcing memher is properly embedded. Thereafter the impregnation of the fiber layer may be carried on as before. In this way, extremely light, strong and durable structures may be prepared, adapted for any of the purposes heretofore mentioned.

The accompanying drawing illustrates a simple form of apparatus suitable for carrying out the method, the figure being a vertlcal sectionalview- In this figure, l illustrates a suitable support or container connected with a suction device by one or more pipes 2. 3 indicates the foraminous bed supported in any suitable manner within the container 1. The article 4 being molded is here indicated as a flat plate or board,

but obviously may be of any desired form,

depending upon the contour of the foraminated bed. An embedded reinforcing element such as a wire mesh, is indicated at 5 which, however, may be omitted.

I claim 1. Method of producing an article comprising a fibrous body and a cementitious binder, which consists in forming the article upon a for'aminous support from a mixture containing fiber and magnesia, and then subjecting the formed article while carried by said support to the action of a solution of a magnesium salt.

2. Method of producing a sheet or article comprising a fibrous body and a cementitious binder, which consists in depositing a mixture of fiber and magnesia upon a foraminous base to form the article, and then treating the formed article while carried by said support with a solution of a magnesium salt while maintaining a difference of pressure on opposite sides thereof.

3. Method of producing an article comprising a fibrous body and a cementitious binder, which consists in suspending a fiber and magnesia in a liquid, depositing them simultaneously therefrom in the form of a sheet or article upon a foraminous support, and then treating the deposited layer while carried by said support with a solution con- ,taining magnesium chlorid to convert the magnesia into oxychlorid.

4;. Method of producing an article comprising a fibrous body and a cementitious binder, which consists in suspending a fiber and magnesia in a liquid, depositing them simultaneously therefrom in the form of a sheet or article upon a foraminous support, and then causing a solution containing magnesium chlorid to flow through the deposited layer'while carried by said support until the magnesia therein is converted into oxychlorid.

In testimony whereof I afiix my signature.

DAVID C. COLLIER. 

